In recent years, secondary batteries (hereinafter, also simply referred to as batteries) typified by lithium ion batteries have been widely used as drive power sources of a hybrid vehicle, an electric vehicle, and others as well as compact electronic devices such as a cellular phone, a notebook-size computer, and a digital camera. In particular, batteries to be used in vehicles such as a hybrid vehicle and an electric vehicle are required to output high power. This requires to increase the size of each battery and connect a plurality of batteries in series or in parallel during use. In a case where the secondary battery is used in a vehicle or the like, particularly high safety is demanded. Regarding such a battery, for example, Patent Document 1 discloses a battery including a pressure-type current interrupt mechanism configured to break current when the internal pressure of a battery case rises, in order to enhance the safety of the battery.